Project Solutions (2011/07/27)

iAccess--an intelligent access control system （1）

Published:2011/7/27 22:39:00 Author:Li xiao na

Design by I. Joostens Surveys show that people are feeling increasingly less safe. Consequently, protecting property and buildings receives more and more attention these days. One of the aspects of such protection is access control. The system described here goes further than most such systems. Besides granting persons selective access to specific areas, iAccess allows you to check ...   (View)

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Audio Power Amps on the Internet

Published:2011/7/27 22:33:00 Author:Phyllis

Fewer components, better sound? By Harry Boggen Audio lovers will no doubt drool over the new Elektor preamp with digital control published in this issue. This, of course, calls for a matching power amplifier! Sure, there are enough high-quality Elektor designs to choose from, but it may also be interesting to trawl the Internet for alternative designs from all over the world. (View)

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Parallel Port Mains Switching Interface--switch radio controlled mains sockets on and off from a PC （3）

Published:2011/7/27 22:20:00 Author:Li xiao na

by K. Heiden Construction The simplest way to construct the interface circuit is to use matrix stripboard. The components are all widely available and so should be easy to obtain. A suitable latching relay for RE1 is available for example from Conrad Electronics (order code 50 40 60). For RE2 practically any small 12 V relay can be used. As can be seen from the circuit diagr...   (View)

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Drop-in Microcontroller Board （3）

Published:2011/7/27 21:39:00 Author:Phyllis

Building it Having purchased the printed circuit board and all components you are ready to start building the circuit. As shown in Figure 4, the PCB consists of two sections that are easily separated using a hacksaw. One section is for the interface with the PC, the other, for the drop-in module proper. (View)

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Drop-in Microcontroller Board （2）

Published:2011/7/27 21:35:00 Author:Phyllis

Hardware The starting point for your experiments with this chip is a piece of hardware we developed that could be ’dropped’ into several circuits. The circuit diagram of the drop-in module may be found in Figure 2. Even a cursory glance at the drawing should convince you that simplicity is trumps. Thanks to the multifunctional character of the PSD813 chip, this bit of hardw...   (View)

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Drop-in Microcontroller Board （1）

Published:2011/7/27 21:29:00 Author:Phyllis

An 80C32 jack-of-all-trades At the heart of this remarkably compact microcontroller board you’ll find an ingenious bit of integration technology. The combination acts as a versatile plug-in module for lots of applications requiring some form of intelligent control. Thanks to the extensive software that comes with the board and the presence of a PC interface, our drop-in board is excellent for hardw...   (View)

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FlexiPanel IR Infrared glue for micros and PDAs (1)

Published:2011/7/27 4:13:00 Author:Amy

By Jan Buifing and Luc Lemmens IrDA sure looks like an attractive medium for conveying data across small distances. Unfortunately, the associated hardware gener­ally causes sour faces, and is not just ’playing’ hard to get. Those days are over. Paris-based Hoptroff sarl (in the UK: Flexipanel Ltd.) recently announced the release of an IrDA module (also called ‘irGUI module’ or ‘...   (View)

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Up, Up and Away

Published:2011/7/27 3:38:00 Author:Amy

By David Daamen Telemetry applied to modelling sometimes pro­duces astounding results — especially if elec­tronics is part of the payload... Model construction and electronics seem to get on like a house on fire, new challenges appearing any time these two fields of interest are combined. The results are often rather spe­cial. For example, Olivier Humez on his website |1...   (View)

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Project C+ Solved （2）

Published:2011/7/27 3:02:00 Author:Amy

By Prof. Martin Ohsmann Causality Causality states that in our physical world the flow of events is always the same: first, cause, then effect. You are aware of pain in your thumb after you hit it with a hammer and not before the unfortunate accident. If this prin­ciple is universal, is it possible in our simple circuit that a signal arrives at the output of a filter before it w...   (View)

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Introduction of The 868MHz and 915MHz Drop-In RF Modules

Published:2011/7/27 2:53:00 Author:Phyllis

XEMICS’ 868MHz and 915MHz Drop-In RF modules have been designed to facilitate the development of wireless communication applications and to reduce the time to market as they can be soldered directly onto a host board to add RF capabilities. Using these DP1203 modules ranges of up to several kilometers may be achieved, through high output power and excellent sensitivity. The 868MHz module is ETSI pre-certified and t...   (View)

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Project C+ Solved （1）

Published:2011/7/27 2:21:00 Author:Amy

By Prof. Martin Ohsmann The circuit described in the April 2004 edition of Elektor Electronics certainly gave rise to a lot of head scratching and raised eyebrows when it was shown to produce an output pulse ahead of the input pulse. Is it possible that such a simple circuit can turn the principle of causality on its head? Read on... The idea for this article began when a student as...   (View)

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The SMD Chip LED Produced by Components Bureau

Published:2011/7/27 2:02:00 Author:Li xiao na

Components Bureau is the Cambridge shire-based passive component and specialist capacitor distribution company, which is able to provide the service from franchised component distributin to the PCB assembly. It has decades of history, so it can offer the customer the solutions which can be multi-faceted. A range of passive, opto and electro-mechanical solut...   (View)

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Everything You Need to Know to Drive a Stepper Motor (4)

Published:2011/7/27 1:37:00 Author:Amy

By Horst Hubert Operation The driver circuit for the stepper motor consists of two identical halves, so we only need to look at one half. The signal at the input is converted by T9 into a square wave with an amplitude equal to that of the supply voltage to the circuit. This is neces­sary because the driving signal usu­ally has a much smaller amplitude, such as 3.3 or 5 V. ...   (View)

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